Typescript returns errors regarding ID that is undefined about dexie.js HOT 11 CLOSED

  function moveFileUp(id: number) {
    db.transaction("rw", db.files, async () => {
      const fileToMove = await db.files.get(id);
      if (fileToMove) {
        const pos = fileToMove.position;
        // We try to update: if no object is updated, there is no object above
        const nbObjectModified = await db.files.where({position: pos-1}).modify(item => {++item.position});
        if (nbObjectModified == 1) {
          await db.positions.where({id: id}).modify(item => {--item.position});        
        }
      }
    });
  }

…

<button on:click={() => moveFileUp(file.id)}><Icon.CaretUpOutline/></button>

Error: Argument of type 'number | undefined' is not assignable to parameter of type 'number'.
  Type 'undefined' is not assignable to type 'number'. (ts)
        <button on:click={() => moveFileUp(file.id)}><Icon.CaretUpOutline/></button>

Error: Argument of type 'number' is not assignable to parameter of type 'File | "id"'. (ts)

Error: No overload matches this call.
  Overload 1 of 4, '(key: "id"): PromiseExtended<File | undefined>', gave the following error.
    Argument of type 'number' is not assignable to parameter of type '"id"'.
  Overload 2 of 4, '(equalityCriterias: { [key: string]: any; }): PromiseExtended<File | undefined>', gave the following error.
    Argument of type 'number' is not assignable to parameter of type '{ [key: string]: any; }'. (ts)
    db.transaction("rw", db.files, async () => {
      const fileToMove = await db.files.get(id);
      if (fileToMove) {

Error: Argument of type '{ name: string; slug: string; description: string; position: number; }' is not assignable to parameter of type 'Deck'.
  Property 'id' is missing in type '{ name: string; slug: string; description: string; position: number; }' but required in type 'File'. (ts)
      db.transaction("rw", db.files, async () => {
        const id = await db.files.add({
          name: newFileName,
          slug: slug,
          description: "Click me to edit this description",
          position: $decks.length
        });

// Each file is made of decks
export interface File {
  // Make sure to update the associated class below
  id: number;
  name: string; //
  slug: string;
  description: string;
  position: number;
}

export class MyDb extends Dexie {
  files!: Table<File, 'id'>; 

  constructor(name : string) {
    super(name);
    this.version(1).stores({
      files: '++id, name, slug, position', // Primary key and indexed props
    });
  }
}